Lightweight, plastic containers are used in myriad applications. However, certain applications demand or make desirable particular features of containers. For example, in the high-volume production of animal feed supplements and similar materials, it is desirable to provide containers which are nestable, particularly when empty, and are also vertically stackable when filled with the material for which the container is designed. Flowable animal feed supplements are often containerized at a relatively high temperature of the supplement material. Filling molded plastic containers at elevated temperatures of the material disposed in the containers tends to weaken the containers and prevent stacking the containers one on top of the other, since the lower-most or at least lower ones of the containers in the stack tend to deform under the weight of the containers stacked above.
Of course, prior to filling containers, it is desirable to minimize the space occupied by such items by nesting the containers one inside the other while also providing for easy separation of the containers as they are processed to be filled with the material they are to contain. Accordingly, certain engineering problems have persisted in the development of nestable and stackable containers used for various applications, including the application mentioned hereinabove. It is to overcome the problems associated with prior art containers that the present invention has been developed.
The present invention provides an improved nestable and stackable container, particularly one formed of molded plastic and being adapted to contain relatively high-density material, which may be loaded into the container at an elevated temperature.
In accordance with one aspect of the present invention, a nestable and stackable container is provided which comprises a molded plastic bucket or tub which includes, in combination, an improved sidewall configuration which adds strength to the container, particularly for applications wherein filled containers are vertically stacked one on top of the other. The container sidewall is also joined to a bottom wall of the container in a manner which allows transfer of forces acting on the container through the sidewall directly to a surface supporting the container in a manner which resists or reduces the likelihood of bulging of the container at the juncture between the sidewall and bottom wall. Moreover, the configuration of the sidewall also enhances the nestability and vertical stackability of the container.
In accordance with another aspect of the invention, a stackable and nestable container is provided which is preferably formed of molded plastic, includes a sidewall which is characterized by alternate, inwardly facing and outwardly facing channel portions, the channel portions being tapered, generally from a top edge of the container to a bottom edge of the container sidewall. Still further, the outwardly facing channel portions may be reinforced by a vertical, generally central rib extending along each of the outwardly facing channel portions.
Still further, the present invention provides a container with improved nestability provided by a sidewall with alternate inward and outward facing channel portions which are tapered from, generally, a top edge of the container toward a bottom wall of the container and with circumferentially-spaced nesting stops dimensioned to limit the amount of insertion of one container within the other.
Those skilled in the art will further appreciate the above-mentioned advantages and superior features of the container of the present invention upon reading the detailed description, which follows in conjunction with the drawing.